A child died and seven others got injured in Jalpaiguri district on Thursday evening when his father tried to prise open a suspected mortal shell used by the defence forces.

The shell, sources said, was floating in the Teesta. Taibur Rehman, a resident of Panditpara in Champadanga of Kranti block, which is on the left bank of the river, had found it and taken it home.

There, as Rehman tried to open the shell in the presence of several onlookers, including his son Sainur Alam, 3, it exploded. The blast killed Sainur. Rehman and six others suffered serious injuries and had to be hospitalised.

The incident occurred a few hours after the Sikkim government issued an advisory in the Himalayan state, alerting people not to collect ammunition or explosives, if any, from the river. As the Teesta has damaged defence installations in the state, it is suspected that the river has swept away several such items.

Sources said while some other Panditpara residents collected shells and boxes, suspected to be packed with explosives, from the Teesta, they dumped those in deserted areas after news of the blast spread.

Mahua Gope, the Jalpaiguri district Trinamul chief, rushed to the hospital after the incident to meet the injured.

Gope appealed to people not to collect items that the Teesta brought downstream, highlighting the risks.

Officials of Jalpaiguri district police said they were making public announcements to this effect along the banks.